Covering 71 percent of Earth’s surface, the oceans play

Question

Covering 71 percent of Earth’s surface, the oceans play an essential role in maintaining the conditions for human existence on land, moderating temperature by the absorption of heat and carbon dioxide, and giving pure water back to the atmosphere through evaporation

Option AOption BOption COption DOption E

(This question is from Official Guide. Therefore, because of copyrights, the complete question cannot be copied here. The question can be accessed at GMAT Club)

Solution

Sentence Analysis

Let’s understand the structure of the sentence:

Covering 71 percent of Earth’s surface,

the oceans play an essential role in

maintaining the conditions for human existence on land,

moderating temperature by the absorption of heat and carbon dioxide,

and giving pure water back to the atmosphere through evaporation

The sentence starts with a verb-ing modifier modifying “the oceans”. The oceans cover 71 percent of Earth’s surface. They play an essential role in doing three things as given above.

The meaning of the sentence is clear and logical. All the elements are in the list are parallel (verb-ing forms – maintaining, moderating, and giving)

The original sentence, thus, has no errors.

Option Analysis

(A) Correct.

(B) Incorrect. With the sentence structure in this option, there is nothing parallel to “giving pure water” before ‘and’ (in the non-underlined part).

(C) Incorrect. In this option, “by moderating” and “giving pure water” are not parallel to each other and to any other thing in the sentence.

(D) Incorrect. With the sentence structure in this option, there is nothing parallel to “giving pure water” before ‘and’ (in the non-underlined part).

(E) Incorrect. With the sentence structure in this option, there is nothing parallel to “giving pure water” before ‘and’ (in the non-underlined part).

This question highlights the importance of reading the non-underlined part. In three out of the four incorrect options, one needs to have read the non-underlined part to understand the error. The process that I recommend starts with understanding the meaning of the sentence for which you have to read the entire sentence, including the non-underlined part.

About Chiranjeev Singh

An Alumnus of IIM Ahmedabad and with scores of 780 (2017) and 770 (2013) on GMAT and 99.98%ile on CAT, Chiranjeev is one of the most qualified GMAT tutors in India. Chiranjeev has earlier served as Director of Curriculum at e-GMAT.
Chiranjeev has been helping students ace GMAT since 2012. He follows a concept-based methodology to teaching GMAT and is very committed to student success.
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